*, *:before,
*:after {
    box-sizing: border-box;
}

html {
    font-family: 'Roboto Condensed', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    height: 100%;
    color: #ECEFF1;
    background-image: radial-gradient(#4f6875, #263238);
}

.toggle {
    position: relative;
    display: block;
    margin: 0 auto;
    width: 150px;
    height: 60px;
    color: white;
    outline: 0;
    text-decoration: none;
    border-radius: 100px;
    border: 2px solid #546E7A;
    background-color: #263238;
    transition: all 500ms;
}

.toggle:active {
    background-color: #1c2429;
}

.toggle:hover:not(.toggle--moving):after {
    background-color: #455A64;
}

.toggle:after {
    display: block;
    position: absolute;
    top: 4px;
    bottom: 4px;
    left: 4px;
    width: calc(50% - 4px);
    line-height: 45px;
    text-align: center;
    text-transform: uppercase;
    font-size: 20px;
    color: white;
    background-color: #37474F;
    border: 2px solid;
    transition: all 500ms;
}

.toggle--on:after {
    content: 'On';
    border-radius: 50px 5px 5px 50px;
    color: #66BB6A;
}

.toggle--off:after {
    content: 'Off';
    border-radius: 5px 50px 50px 5px;
    transform: translate(100%, 0);
    color: #f44336;
}

.toggle--moving {
    background-color: #1c2429;
}

.toggle--moving:after {
    color: transparent;
    border-color: #435862;
    background-color: #222c31;
    transition: color 0s, transform 500ms, border-radius 500ms, background-color 500ms;
}

h1 {
    font-size: 64px;
    margin-top: 0;
    margin-bottom: 50px;
}